*{
    margin: 0;
    padding: 0;
}
.abc{
    margin: 5px;
}
.yi{
    width:100vw;
    height: 100vh;
    background-color: #000453;
}
.da{
    display: flex;
    justify-content: space-between;
}
.zhong{
    display: flex;
    justify-content: space-between;
}
.xiao{
    display: flex;
    justify-content: space-between;
}